1. Field of the Invention
The present invention relates to a needle member especially suited for use as a hypodermic needle and for use with a catheter. More particularly, the present invention relates to a needle member that includes a flash chamber for the detection of fluid therein.
2. Related Art
Needle and catheter arrangements for removal or insertion of fluids through the epidermis of a patient are well known. Healthcare workers using needles and catheters often have difficulty in accurately locating and puncturing a vein inside a patient, making necessary multiple insertions of the needle which cause discomfort to the patient. One mechanism to aid in locating veins is a flash chamber, a clear or translucent chamber located behind the proximate end of the cannula, allowing the user to see the blood as it exits the needle. This first showing of blood is called xe2x80x9cflashxe2x80x9d. By watching for flash, the user can verify that the tip of the hypodermic needle has entered the vein and thus the user can cease penetration of the patient""s flesh before the distal end of the needle penetrates the far side of the vein.
Another aid to healthcare workers attempting accurate placement of cannulae is a hypodermic needle which allows insertion at a wide range of angles, especially angles in which the hypodermic needle is substantially parallel to the epidermis of the patient.
Yet a third feature which aids venipuncture is a catheter and hypodermic needle arrangement which is modular and allows easy addition and removal of accessories as required.
U.S. Pat. No. 5,009,642 to C.R. Sahi, dated Apr. 23, 1991 and entitled xe2x80x9cSELF-BLUNTING NEEDLE ASSEMBLY WITH A CATHETER, AND CATHETER ASSEMBLY USING THE SAMExe2x80x9d, discloses a self-blunting needle assembly (10) for use with a catheter (40). The needle assembly (10) includes a needle (12) that comprises a transparent fluid collection tube (or xe2x80x9cflash chamberxe2x80x9d) (24) secured to a needle shaft (14) (see FIG. 4). The needle (12) also includes an elongate probe (30) movably disposed within the needle shaft (14). Prior to use, the catheter is placed over the needle shaft and is positioned to engage the probe. The needle shaft is then used to introduce the catheter into a vein. When venipuncture is achieved, blood flows through the needle shaft into the collection tube, giving the user a visual indication that the needle and catheter are properly positioned. The needle assembly can then be withdrawn to allow use of the catheter in a conventional manner. Since the catheter engages the probe, withdrawal of the needle member from the catheter advances the probe within the needle so that the withdrawn needle assembly becomes blunted after having been used. The collection tube and needle shaft are both generally cylindrical in configuration and are co-axially disposed relative to each other. The diameter of the collection tube, however, is several times greater than the diameter of the needle shaft and catheter, so that the collection tube limits the angles at which the needle may be introduced into the patient""s vein.
U.S. Pat. 5,374,252 to Banks et al, dated Dec. 20, 1994 and entitled xe2x80x9cLOCKING PNEUMONEEDLExe2x80x9d, discloses a pneumoneedle that comprises a cannula (20) mounted in a housing (12) (see FIG. 1). The housing (12) also contains a tubular protector (or xe2x80x9cblunting memberxe2x80x9d) (31) disposed within the cannula and movable between a retracted position in which the sharp tip of the cannula is exposed and a deployed position in which the blunt end (32) of the protector extends beyond the sharp tip of the cannula. The protector (31) is tubular and has a distal aperture (36) that is exposed when the protector is moved to the deployed position. There is also a proximal aperture (35) that opens to an internal fluid passageway portion of the housing (12). A fluid conduit (8) in the housing communicates with fluid passageway portion (18) and extends at an angle relative to the longitudinal axis of the needle cannula. The device is used for introducing an insufflating gas into the abdominal cavity of a patient via the fluid conduit. To determine whether the sharpened tip of the cannula, and therefore the distal aperture of the protector, are properly positioned, a saline/vacuum test must be performed. In this test, the device is primed with a small reserve of saline solution via the fluid conduit (8) and the device is inserted into the patient. The patient""s abdomen is manipulated and if fluid communication has been established between the abdominal cavity and the device, the saline will be seen to surge. There is no indication or suggestion that the level of saline can be seen through the device housing, i.e., that the housing is translucent, or that the device may be adapted for intravenous use or that the fluid conduit be used for anything other than introducing an insufflating gas into the protector. In the medical field, pneumoneedles are considered to relate to a function that is disparate from that of intravenous fluid flow and the knowledge in the art pertaining to pneumoneedles is not seen as analogous or pertinent to intravenous needles.
U.S. Pat. No. 5,120,319 to Van Heugten et al, dated Jun. 9, 1992 and entitled xe2x80x9cFLASH TUBE FOR INTRAVENOUS CATHETERxe2x80x9d, discusses some of the problems associated with flash chambers. As pointed out in this reference, when using small needles in small veins, quick flashback and quick reaction speed are more important than in larger veins. However, a larger flashback chamber is necessary when examining the blood flow to verify that it is continuing and thus there is a trade-off between large and small flash chambers. Van Heugten et al teaches a flash chamber having a capillary tube which will quickly fill with blood. Owing to the diffraction properties of the glass tube, the outside diameter of the tube appears to be red. This is combined with a conventional, larger, flash chamber allowing healthcare workers to verify continued flow of blood. While Van Heugten et al aids the healthcare worker in detecting the flash, the presented apparatus does not assist in successful venipuncture at angles close to parallel with the epidermis of the patient nor does Van Heugten et al teach any self-blunting mechanism.
U.S. Pat. No. 5,697,914 to G.L. Brimhall, dated Dec. 16, 1997 and entitled xe2x80x9cCONTROL FORWARD/FLASHBACK FORWARD ONE HAND INTRODUCER NEEDLE AND CATHETER ASSEMBLYxe2x80x9d, is another non-self-blunting design which improves visibility of flash, by using an angled flash chamber. Brimhall also teaches a method for the healthcare worker/user to withdraw the needle within the catheter. However, Brimhall""s needle is not automatically self-blunting, nor is there any method other than the angled nature of the flash chamber, to improve visibility of blood within the flash chamber. Finally, the wide fins projecting at various angles from the body of Brimhall""s catheter assembly restrict motion at some orientations of the assembly.
It would be advantageous to provide a needle member with improved flash visualization which allows easy placement of the needle at any orientation even at angles parallel to the epidermis of the patient, and with easy access to a luer connection. It would further be advantageous if the catheter and needle assembly were held aligned while the catheter is removed from the needle assembly after insertion into the patient.
The invention provides a needle member comprising a needle cannula having a needle axis and a housing on which the needle cannula is mounted, the housing being at least partially translucent and dimensioned and configured to define a translucent flash chamber offset from but substantially parallel to the needle axis and in fluid communication with the needle cannula.
In another aspect, the invention provides a needle member comprising a needle cannula having a needle axis and a housing, the needle cannula mounted on the housing, the housing dimensioned and configured to define an access port offset from but substantially parallel to the needle axis.
Another aspect of the invention provides a needle member comprising a needle cannula having a needle axis and a housing on which the needle cannula is mounted, the housing being at least partially translucent and dimensioned and configured to define a translucent flash chamber in fluid communication with the needle cannula, and a display member disposed within the housing.
Another aspect of the invention provides a display member disposed within the flash chamber.
Another aspect of the invention provides a display member comprising a plurality of slats.
Yet another aspect of the invention provides a display member comprising a perforated tube disposed in the flash chamber.
Yet another aspect of the invention provides a blunting member comprising an elongate probe that has a blunt tip, the probe being disposed within the needle cannula. The probe is dimensioned and configured to be accommodated within the needle cannula while leaving the needle cannula open to fluid flow therethrough and the blunting member is movable between a retracted position in which the blunt tip of the blunting member is disposed within the needle cannula and a deployed position in which the blunt tip protrudes outwardly of and thereby blunts the tip of the needle cannula.
Yet another aspect of the invention provides a probe which is hollow and is in fluid communication with the flash chamber.
Yet another aspect of the invention provides a probe which is solid.
Yet another aspect of the invention provides a needle member comprising a needle cannula having a needle axis and a housing, the needle cannula mounted on the housing, the housing being at least partially translucent and dimensioned and configured to define a flash chamber substantially offset from but substantially parallel to the needle axis and in fluid communication with the needle cannula, and a display member having an enhanced blood surface area disposed within the housing.